The present invention relates to a condition monitoring and battery recharging system that can be used to monitor a characteristic of a dynamic member. More particularly, the present invention relates to a system for monitoring a characteristic such as speed, vibration, or temperature of a dynamic member such as a rotatable member while simultaneously powering the monitoring system using a signal generated by the monitoring system.
The various types of machinery generally found in an industrial setting will often utilize bearings, speed reducers, motors, or other such mechanical components. For example, a single conveyor will frequently be equipped with multiple pillow block or flange bearings to support its various rotatable shafts. Speed reducers or other gear boxes may be utilized to transmit mechanical power to the machinery from a suitable prime mover.
The status of these mechanical and electrical components is often monitored during operation to determine when some form of corrective action should be taken. For example, the temperature of a bearing can be monitored to lessen the occurrence of overheating which can cause failure. It is also frequently desirable to monitor the rotational speed of a rotatable member such as a shaft to which a bearing is attached, or a shaft of a prime mover such as an electrical motor. Also, vibration may be monitored. To facilitate such monitoring, the various mechanical components can be equipped with a plurality of sensors.
The signal information provided by the various sensors may be processed at a central monitoring controller. In the past, however, dedicated transmission lines have typically been provided for each of the sensors. As a result, several transmission lines could be required between each of the mechanical components and a central monitoring facility. To reduce the number of transmission lines, it has been proposed to provide a central communication bus to thereby simplify the provided wiring. Such a system is disclosed in U.S. Pat. No. 5,844,501, owned by Applicant's Assignee and incorporated by reference herein.
While such system is useful for its intended purpose, wiring is still required to be connected to the sensors disposed on each of the electronic components. Also, a separate power source must be provided to each sensor device if it includes any non-passive components such as a processor, transmitter, etc. To further reduce wiring requirements, batteries may be provided for non-passive components in such systems. An inherent drawback of batteries is their finite life, requiring periodic replacement or recharging of the batteries.